This is a proposal to continue a program of research on essential memory skills involved in disregarding irrelevant information in memory (selective remembering) and to investigate the role of comprehension process in the adoption of effective mnemonic strategies on a variety of tasks. The failure to ignore irrelevant information in memory may interfere with the processing of relevant information resulting in a decrease in learning efficiency. Both mentally retarded and normal children ranging in age from 7 to 15 years of age will be studied. In the selective remembering task, the child will periodically be instructed to forget information which he/she was previously instructed to remember. Performance on this task depends on intelligence, age, and comprehension of the task demands. The first two experiments will focus on two aspects of selective remembering (a) the mechanisms responsible or adequate selective remembering strategies and (b) the use of these strategies in the comprehension and retention of gist of discourse. Five additional experiments will investigate the role of comprehension processes in strategy adoption. Those will include studies of (a) developmental changes in knowledge of formal testing situations and the possible influence of that knowledge on the child's conceptualization of a memory task; (b) the effect of attempts to change the child's conceptualization of a memory task in order to improve memory performance; (c) the contribution of several distinct components of comprehension processes to adoption of mnemonic sstrategies; (d) the locus of task-constraint effects on strategy use and task comprehension and (e) the variables's contributing to comprehension in a situation with memory for a purpose. These studies will contribute to understanding the differences in the developmental course of memory development in normal and mentally retarded children and will relate these differences to a general conceptual framework for comprehension and the use of effective mnemonic strategies.